=====================================================
BUG: KMSAN: uninit-value in ipt_mangle_out net/ipv4/netfilter/iptable_mangle.c:61 [inline]
BUG: KMSAN: uninit-value in iptable_mangle_hook+0x60b/0x700 net/ipv4/netfilter/iptable_mangle.c:81
CPU: 1 PID: 11067 Comm: syz-executor.0 Not tainted 5.6.0-rc2-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
Call Trace:
 __dump_stack lib/dump_stack.c:77 [inline]
 dump_stack+0x1c9/0x220 lib/dump_stack.c:118
 kmsan_report+0xf7/0x1e0 mm/kmsan/kmsan_report.c:118
 __msan_warning+0x58/0xa0 mm/kmsan/kmsan_instr.c:215
 ipt_mangle_out net/ipv4/netfilter/iptable_mangle.c:61 [inline]
 iptable_mangle_hook+0x60b/0x700 net/ipv4/netfilter/iptable_mangle.c:81
 nf_hook_entry_hookfn include/linux/netfilter.h:135 [inline]
 nf_hook_slow+0x16e/0x400 net/netfilter/core.c:512
 nf_hook include/linux/netfilter.h:262 [inline]
 __ip_local_out+0x69b/0x800 net/ipv4/ip_output.c:114
 ip_local_out+0xa4/0x1d0 net/ipv4/ip_output.c:123
 iptunnel_xmit+0x899/0xe00 net/ipv4/ip_tunnel_core.c:81
 udp_tunnel_xmit_skb+0x52a/0x650 net/ipv4/udp_tunnel.c:192
 geneve_xmit_skb drivers/net/geneve.c:929 [inline]
 geneve_xmit+0x28ed/0x2c20 drivers/net/geneve.c:1004
 __netdev_start_xmit include/linux/netdevice.h:4524 [inline]
 netdev_start_xmit include/linux/netdevice.h:4538 [inline]
 xmit_one net/core/dev.c:3470 [inline]
 dev_hard_start_xmit+0x531/0xab0 net/core/dev.c:3486
 __dev_queue_xmit+0x37de/0x4220 net/core/dev.c:4063
 dev_queue_xmit+0x4b/0x60 net/core/dev.c:4096
 packet_snd net/packet/af_packet.c:2967 [inline]
 packet_sendmsg+0x8347/0x93b0 net/packet/af_packet.c:2992
 sock_sendmsg_nosec net/socket.c:652 [inline]
 sock_sendmsg net/socket.c:672 [inline]
 ____sys_sendmsg+0x12b6/0x1350 net/socket.c:2343
 ___sys_sendmsg net/socket.c:2397 [inline]
 __sys_sendmmsg+0x5b6/0xc90 net/socket.c:2487
 __do_sys_sendmmsg net/socket.c:2516 [inline]
 __se_sys_sendmmsg+0xbd/0xe0 net/socket.c:2513
 __x64_sys_sendmmsg+0x56/0x70 net/socket.c:2513
 do_syscall_64+0xb8/0x160 arch/x86/entry/common.c:296
 entry_SYSCALL_64_after_hwframe+0x44/0xa9
RIP: 0033:0x45c679
Code: ad b6 fb ff c3 66 2e 0f 1f 84 00 00 00 00 00 66 90 48 89 f8 48 89 f7 48 89 d6 48 89 ca 4d 89 c2 4d 89 c8 4c 8b 4c 24 08 0f 05 <48> 3d 01 f0 ff ff 0f 83 7b b6 fb ff c3 66 2e 0f 1f 84 00 00 00 00
RSP: 002b:00007ffcc5188618 EFLAGS: 00000246 ORIG_RAX: 0000000000000133
RAX: ffffffffffffffda RBX: 0000000001d48914 RCX: 000000000045c679
RDX: 0000000000000002 RSI: 0000000020000f40 RDI: 000000000000003c
RBP: 000000000076bf00 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 00000000ffffffff
R13: 00000000000008d2 R14: 00000000004cb58a R15: 000000000076bf0c

Uninit was stored to memory at:
 kmsan_save_stack_with_flags mm/kmsan/kmsan.c:144 [inline]
 kmsan_internal_chain_origin+0xad/0x130 mm/kmsan/kmsan.c:310
 __msan_chain_origin+0x50/0x90 mm/kmsan/kmsan_instr.c:165
 iptunnel_xmit+0xaea/0xe00 net/ipv4/ip_tunnel_core.c:75
 udp_tunnel_xmit_skb+0x52a/0x650 net/ipv4/udp_tunnel.c:192
 geneve_xmit_skb drivers/net/geneve.c:929 [inline]
 geneve_xmit+0x28ed/0x2c20 drivers/net/geneve.c:1004
 __netdev_start_xmit include/linux/netdevice.h:4524 [inline]
 netdev_start_xmit include/linux/netdevice.h:4538 [inline]
 xmit_one net/core/dev.c:3470 [inline]
 dev_hard_start_xmit+0x531/0xab0 net/core/dev.c:3486
 __dev_queue_xmit+0x37de/0x4220 net/core/dev.c:4063
 dev_queue_xmit+0x4b/0x60 net/core/dev.c:4096
 packet_snd net/packet/af_packet.c:2967 [inline]
 packet_sendmsg+0x8347/0x93b0 net/packet/af_packet.c:2992
 sock_sendmsg_nosec net/socket.c:652 [inline]
 sock_sendmsg net/socket.c:672 [inline]
 ____sys_sendmsg+0x12b6/0x1350 net/socket.c:2343
 ___sys_sendmsg net/socket.c:2397 [inline]
 __sys_sendmmsg+0x5b6/0xc90 net/socket.c:2487
 __do_sys_sendmmsg net/socket.c:2516 [inline]
 __se_sys_sendmmsg+0xbd/0xe0 net/socket.c:2513
 __x64_sys_sendmmsg+0x56/0x70 net/socket.c:2513
 do_syscall_64+0xb8/0x160 arch/x86/entry/common.c:296
 entry_SYSCALL_64_after_hwframe+0x44/0xa9

Uninit was created at:
 kmsan_save_stack_with_flags mm/kmsan/kmsan.c:144 [inline]
 kmsan_internal_poison_shadow+0x66/0xd0 mm/kmsan/kmsan.c:127
 kmsan_slab_alloc+0x8a/0xe0 mm/kmsan/kmsan_hooks.c:82
 slab_alloc_node mm/slub.c:2793 [inline]
 __kmalloc_node_track_caller+0xb40/0x1200 mm/slub.c:4401
 __kmalloc_reserve net/core/skbuff.c:142 [inline]
 __alloc_skb+0x2fd/0xac0 net/core/skbuff.c:210
 alloc_skb include/linux/skbuff.h:1051 [inline]
 alloc_skb_with_frags+0x18c/0xa70 net/core/skbuff.c:5766
 sock_alloc_send_pskb+0xada/0xc60 net/core/sock.c:2242
 packet_alloc_skb net/packet/af_packet.c:2815 [inline]
 packet_snd net/packet/af_packet.c:2910 [inline]
 packet_sendmsg+0x66a0/0x93b0 net/packet/af_packet.c:2992
 sock_sendmsg_nosec net/socket.c:652 [inline]
 sock_sendmsg net/socket.c:672 [inline]
 ____sys_sendmsg+0x12b6/0x1350 net/socket.c:2343
 ___sys_sendmsg net/socket.c:2397 [inline]
 __sys_sendmmsg+0x5b6/0xc90 net/socket.c:2487
 __do_sys_sendmmsg net/socket.c:2516 [inline]
 __se_sys_sendmmsg+0xbd/0xe0 net/socket.c:2513
 __x64_sys_sendmmsg+0x56/0x70 net/socket.c:2513
 do_syscall_64+0xb8/0x160 arch/x86/entry/common.c:296
 entry_SYSCALL_64_after_hwframe+0x44/0xa9
=====================================================